Coca
Negra

Cobalt and ferric chloride are virtually undetectable masking-chemicals.
They are mixed with pure cocaine - perhaps 40% - and later separated out.
In South America, customs' officers often use sniffer dogs that have been turned
into canine junkies. This ensures the dogs will avidly sniff out contraband narcotics. Not only customs' officers rely on animal assistance. Dogs have recently been used as "mules" by cocaine traffickers.